INTERGALACTIC SHOCK WAVE IS BIGGER THAN THE MILKY WAY
Located about 730 million light years from Earth, Abell 3667 is a galaxy cluster in chaos. It’s composed of two clusters of colliding galaxies. This has created an enormous disturbance in the region: a gargantuan shock wave flaring out either side of the merging cluster and visible only in radio wavelengths. A recent study offers the most detailed picture ever of this enormous wave. Using the MEERKAT radio telescope array in South Africa, researchers imaged both halves of the shock wave’s radio component, also called ‘radio relics’.
The shock wave first blasted into being about 1 billion years ago, when the two galaxy clusters that make up Abell 3667 first collided. Galaxy clusters are the most enormous gravitationally bound structures in the universe; when two of them merge, they release the largest amount of energy in a single event since the Big Bang. As the wave shot electrons into space at near-light-speed, the particles tore through magnetic fields in the region, emitting the twin arcs of radio waves. The radio arcs each move at more than 3.3 million miles per hour and are about 13 million light years apart from each other, and each have been measured to be 60 times larger than the entire Milky Way galaxy.